Made available in DSpace on 2014-12-17T14:06:57Z (GMT). No. of bitstreams: 1 AntonioNF_DISSERT.pdf: 3720151 bytes, checksum: 9b23d51efb071c929717b8ea4387b379 (MD5) Previous issue date: 2011-06-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Physical-chemical properties of Ti are sensible to the presence of interstitial elements. In the case of thermochemical treatments plasma assisted, the influence of different active species is not still understood. In order to contribute for such knowledge, this work purposes a study of the role played by the active species atmosphere into the Ar N2 CH4 carbonitriding plasma. It was carried out a plasma diagnostic by OES (Optical Emission Spectroscopy) in the z Ar y N2 x CH4 plasma mixture, in which z, y and x indexes represent gas flow variable from 0 to 4 sccm (cm3/min). The diagnostic presents abrupt variations of emission intensities associated to the species in determined conditions. Therefore, they were selected in order to carry out the chemical treatment and then to investigate their influences. Commercial pure Ti disks were submitted to plasma carbonitriding process using pre-established conditions from the OES measurements while some parameters such as pressure and temperature were maintained constant. The concentration profiles of interstitial elements (C and N atoms) were determined by Resonant Nuclear Reaction Analysis (NRA) resulting in a depth profile plots. The reactions used were 15N(ρ,αγ)12C and 12C(α,α)12C. GIXRD (Grazing Incidence X-Ray Diffraction) analysis was used in order to identify the presence of phases on the surface. Micro-Raman spectroscopy was used in order to qualitatively study the carbon into the TiCxN1 structure. It has been verified which the density species effectively influences more the diffusion of particles into the Ti lattice and characteristics of the layer formed than the gas concentration. High intensity of N2 + (391,4 nm) and CH (387,1 nm) species promotes more diffusion of C and N. It was observed that Hα (656,3 nm) species acts like a catalyzer allowing a deeper diffusion of nitrogen and carbon into the titanium lattice. / As propriedades f?sico-qu?micas do Ti s?o sens?veis ? presen?a de intersticiais. No caso do tratamento termoqu?mico auxiliado por plasma, a influ?ncia das diferentes esp?cies ativas ainda n?o ? bem entendida. A fim de colaborar para tal conhecimento, esse trabalho prop?e um estudo das esp?cies ativas do plasma carbonitretante de N2+Ar+CH4. Foi realizado o diagn?stico por espectroscopia de emiss?o ?ptica (OES) do plasma na mistura xAr+yN2+zCH4, onde x, y e z s?o fluxos vari?veis de 0 a 4 sccm (cm3/min.). Esse diagn?stico apresentou varia??es abruptas de intensidades de emiss?o das esp?cies em determinadas condi??es e estas foram selecionadas para realizar o tratamento termoqu?mico e assim investigar suas influ?ncias. Em seguida, discos de Ti comercialmente puros foram submetidos ao processo de carbonitreta??o por plasma com as condi??es pr?-estabelecidas pelo diagn?stico de plasma enquanto que os par?metros de press?o e temperatura foram mantidos constantes. O perfil de concentra??o dos intersticiais, carbono e nitrog?nio, foi determinado por rea??o nuclear ressonante (NRA) resultando numa curva de perfil em profundidade. As rea??es usadas foram 15N(ρ,αγ)12C e 12C(α,α)12C. Utilizou-se difra??o de raios-X em ?ngulo rasante (GIDRX) para identificar as fases presentes na superf?cie. A espectroscopia micro-Raman foi usada para estudar, de forma qualitativa a estrutura do carbono no TiCxN1-xVerificou-se que a densidade das esp?cies influencia, de maneira mais efetiva que o fluxo de g?s, no processo de difus?o e nas caracter?sticas da camada formada. Alta intensidade das esp?cies N2 + (391,4 nm) e CH (387,1 nm) favorecem a difus?o dos intersticiais C e N. Foi observado que o Hα (656,3 nm) atua como catalisador permitindo a difus?o em maiores profundidades desses intersticiais na estrutura do Ti.